Diesel fuel differs from gasoline in several ways. Diesel fuel is heavier and "oilier" than gasoline. It evaporates much more slowly because it is composed of larger hydrocarbon molecules, which have higher boiling points, typically 150 °C to 370 °C.

How is diesel fuel classified?

Diesel fuel is usually classified as:

Seasonal diesel fuel: Type B or Number 2 – the most commonly used diesel fuel.

Light diesel fuels: Type A or Number 1, for special applications.

Recently, diesel fuel has also been classified by sulphur content: low sulphur and regular sulphur diesel.

What is low sulphur diesel fuel?

Low sulphur diesel fuel (LSD) is fuel that contains less than 500 parts per million
(0.05 wt per cent) sulphur. It is usually used for on-road applications. Since Jan. 1, 1998, all on-road diesel fuel in Canada must be LSD.

What is regular sulphur diesel fuel?

Regular sulphur diesel fuel (RSD) is fuel that contains less than 5,000 parts per million (0.5 wt per cent) sulphur. It is usually used in off-road applications such as farming, forestry and marine.

How can I tell if diesel fuel is low sulphur or regular sulphur?

All on-highway diesel fuel sold in Canada is low sulphur. Since dyed or marked off-road diesel fuel may be regular sulphur or low sulphur, ask your local supplier about the sulphur content of its off-road diesel fuel. In Western Canada, all Petro-Canada diesel fuels sold for off-road use are normally low sulphur.

Yes! All Petro-Canada diesel fuels have satisfactory lubricity as required by the National Standard of Canada for Automotive Low Sulphur Diesel Fuel.

Does Petro-Canada diesel fuel contain a lubricity additive?

All Petro-Canada diesel fuels have suitable lubricity to protect current fuel systems (pumps and injectors). Most of Petro-Canada's diesel fuels have good natural lubricity (even "low sulphur" diesel fuels), especially during the spring, summer and early fall.

Lighter, low cloud point, winter diesel fuels contain a lubricity additive in keeping with the requirements of the National Standard of Canada for Automotive Low Sulphur Diesel Fuel. Petro-Canada recommends that customers avoid routinely adding additional lubricity additive to fuels as high dose rates of some lubricity additives have been found to cause problems such as sticking of plungers, metering valves or fuel injector racks.

Hydrocracking – a severe, high temperature, high pressure refinery process that converts heavy black oil into gasoline and diesel fuel by cracking or breaking up larger molecules, in the presence of hydrogen and a catalyst.

Hydrotreating – a refinery process that reacts a fraction of crude oil with hydrogen at high temperature and pressure, in the presence of a catalyst, to improve colour and odour, and reduce sulphur content.

Low sulphur diesel fuel – fuel that contains less than 500 parts per million (0.05 wt per cent) sulphur, required for on-road applications, and may be used off-road.

Lubricity – The property of diesel fuel that lubricates moving parts in fuel pumps and fuel injectors to minimize wear.

Off-road diesel fuel – refers to diesel fuel that is used for off-road purposes (i.e., mining, farming, marine, etc.). Off-road diesel fuel is frequently dyed red or "marked" to show that it is exempt from provincial road taxes.

Regular sulphur diesel fuel – fuel that contains less than 5,000 parts per million (0.5 wt per cent) sulphur, may not be used on-road, and is usually used in off-road applications such as farming, forestry and marine.